Calligraphy paper

Calligraphy paper is a type of Japanese paper. Japanese paper is a type of paper made with a unique Japanese technique called kamisuki. Since it is made without using pigments, Japanese paper is highly breathable, durable and long-lasting. If we zoom in on a piece of calligraphy paper with an electron microscope, we can see that the fibers are much longer than those of regular paper, and that there is a lot of space between them.

Notebooks

If we look at the paper we normally use under an electron microscope, we can see lots of thin fibers. This is a plant fiber called "pulp," and is mainly made from wood. Paper is made by adding chemicals and pigments to this pulp.
In plain paper used for ordinary notebooks, you can see long and short fibers mixed together along with pigments.
The paper we use so casually is actually made up of fine fibers.

Carbonless copy paper

Carbonless copy paper, which is used for receipts, allows text to be copied without using carbon ink. How is this possible? Let's explore this mystery with an electron microscope.
Looking at the image, we can see round grains attached to the fibers. The larger grains are cushioning material, while the smaller grains are microcapsules containing a special ink. These capsules are broken by the pressure of a pen and react with special chemicals applied to the paper on the copying surface to make copies. (Fig. 1) You can see that carbonless copy paper has been sprayed all over with this type of substance. The cushioning material serves to prevent the microcapsules from breaking too easily.

Lint-free paper

Lint-free paper is used at locations where dust and dirt are strictly prohibited (clean rooms) in factories that handle precision equipment, among other places. It may employ longer fibers or less pigments in order to prevent fine dust and dirt. If we take a look with an electron microscope, we can see that each fiber is tightly intertwined and that there are no clumps of pigment.

Folding paper: red

When colored folding paper is magnified under an electron microscope, the fibers are visible, just like with regular paper, but the overall shape looks like a single mass. Colored folding paper is made by applying paint to white paper. The paint soaks the fibers, making it difficult to distinguish individual fibers, as seen in the image.

Folding paper: golden

Some sheets of folding paper are gold or silver. Are these made with paint like the other colored folding paper?
If we look at gold folding paper under an electron microscope, we are unable to see any fibers at all. Gold folding paper is made by pasting aluminum foil over white paper and then pasting yellow cellophane over the foil to give it the color. Unlike with other colored folding paper, we are unable to see the fibers because there are several layers on top of the regular paper.

New Year's greeting card (regular paper)

We can see that the fibers are tightly intertwined.

New Year's greeting card (inkjet paper)

This type of paper is specially suited to inkjet printing. In inkjet printing, documents are printed out by spraying very small droplets of ink. The special paper used makes the colors look more vivid. The fibers are not visible, even at 500x magnification, but we can see objects that resemble fine grains of sand. This is because of a unique coating that allows the ink to soak in better. The ink soaks into the gaps between the bumps, creating beautiful clear print-outs.

New Year's greeting card (photo inkjet paper)

The difference in appearance between photo inkjet paper and inkjet paper is whether the image is glossy. Gloss makes printed images look like developed photographs. When photographic inkjet paper is magnified under an electron microscope, no fibers are visible. As you can see, it is as flat as a board, without the bumps seen on inkjet paper. This is because paint is applied on top of the fibers to make them glossy.

Toilet paper

Another type of paper that we use without giving it much thought is toilet paper. Its distinguishing feature is that it dissolves in water. When we zoom in, can you see how many gaps there are between each fiber? It looks rather different than paper towels, which do not dissolve easily in water. The presence of more gaps means that the fibers will easily unravel when placed in water.

Paper towels

There are many experimental tools and machines that do not work properly if they have dust or dirt on them. To wipe these off, we use something called a "waste rag." These rags can be made out of cloth or paper. We magnified a rag made of paper (commonly referred to as a "paper towel") under an electron microscope. Paper towels produce little lint and do not readily dissolve in water.
If we look at the image, we can see that there are no pigments, which are believed to be a cause of lint buildup. We can also see that the fibers are thick, flat and tightly intertwined. This prevents the accumulation of dust and dirt, so that the paper towel can be used to clean precision machinery and other tools.